I am a special case because I do a lot of research. Not having anything close to Google Books has made nearly every search engine that’s not Google a nonstarter for me. And it’s not hard to see how other search engines could compete with that—work closely with the Internet Archive to put a really strong front end on that. But Google put the hard work into winning the long-running legal battle to keep that thing alive, and the result is that they now get to benefit from its stickiness for decades to come.
But credit where credit’s due. Google built a good moat, one so good that even people who stay abreast of alternative search engines can struggle to leave its clutches.